The present invention relates to a laser line beam emitting apparatus which is employed as a laser marking apparatus with the emission of laser beam(s) or ray(s) (hereinafter, laser beam) to an objective, and particularly to a laser line beam emitting apparatus, which is directed to the construction industry for measurement of objectives such as walls, ceilings, floor, and etc. of a building under construction, with the emitted beams.
Nowadays, the construction industry uses the laser line beam emitting apparatus in place of the marking (or ink pad) technique, that carpenters or construction workers measure the objectives by drawing a vertical or horizontal line on respective surfaces with a Chinese ink or chalk.
The apparatus produces a laser line beam (a drawn line) by collimating diffusive semiconductor laser beam through a collimator lens therein, and then generating unidirectional diffusion of the collimated laser beam through a cylinder-shaped rod lens therein. In addition, it performs the horizontal or vertical preservation (a horizontal or plumb line) of the laser line beam by the gimbals mechanism. The gimbals mechanism allows for constantly positioning of a laser beam source unit having united hold of the semiconductor laser, and collimator and rod lenses through its holder. In the gimbals mechanism, its pendulum maintains the constant position of the laser beam source unit disposed therein such that even though the laser line beam emitting apparatus inclines downward or upward, it provides the horizontal or plumb laser line beam.
For the gimbals mechanism according to the conventional laser line beam emitting apparatus that it holds shaft(s) by ball bearing(s) which comprise precise parts, crosswise impact force load with respect to the bearing axle produces force in the direction in which the shaft bends, and then such the precise ball bearing become deformed and is damaged.
In addition, the laser line beam emitting apparatus has a mechanical lock to prevent excessively swinging or moving of the laser beam source unit which is assembled into a pendulum, at the carriage, and the mechanical lock locks the laser source unit except of time of the use. The problem is that depending on the structure of mechanical lock, the shaft and the ball bearing to hold the shaft experiences load, and the ball bearing becomes deformed and is damaged by the impact force further applied thereto.
Such the deformation of or damage to the ball bearing make impossible balance of the pendulum, as well as correct emission of the horizontal or vertical beam.
For the above reason, the present applicant has invented and applied for patent on a gimbals mechanism of a laser line beam emitting apparatus, characterized by having a shaft with two steps between up and down. Japanese patent application No. 2000-230326 discloses the invention. The foregoing gimbals mechanism has possible prevention of deformation of or damage to the ball bearing with hold of the shaft, by means of dispersion of the impact force load to the shaft into the shafts comprised of two stages in up and down arrangement.
When the carpenter or construction worker ascertains verticality of objectives such as columns or walls, or level of objectives such as beams, window frames and so on, he employs a plumb instrument or leveler. If a laser line beam emitting apparatus as a laser marking apparatus may perform functions of the plumb instrument or leveler, there is no need of the plummet instrument or the leveler. This will convenience for the users, and reduce bore cost.
In view of the subject matter as previously described, it is the first object of the present invention to provide a laser line beam emitting apparatus having more effective improvement in construction of the gimbals mechanism than the foregoing prior arts. Even though the pendulum is locked by a lock mechanism against the swing, it can take a free position to avoid that it holds with strong force against the shaft in the gimbals mechanism. Hence, the present invention provides a laser line beam emitting apparatus having high durability, which allows for prevention of deformation of and damage to the shaft.
In combination with the foregoing improvement, it is the second object of the present invention to provide a gimbal mechanism undergoing improvement in construction, enabling the use of the laser line beam emitting apparatus as either or both of a plummet instrument and a leveler.
In the laser line beam emitting apparatus according to the present invention, the laser line beam source unit is assembled into the pendulum, which is hung from the gimbals mechanism. The gimbals mechanism comprises a plurality of first horizontal shafts provided in a parallel arrangement; a plurality of second horizontal shafts provided in a parallel arrangement, being at right angles to the first horizontal shafts; and a plurality of links linked in series through respective first and second horizontal shafts. The laser line beam emitting apparatus has a stopper disposed opposite the pendulum therein, and a pressure member disposed on the opposite side from the stopper with respect to the pendulum, having contribution to pressing of the pendulum into the stopper for a stop of swings of the pendulum. Each of the links swings about respective first and second horizontal shafts for positioning of the pendulum into the stopper with maintenance of the balance.
The gimbals mechanism according to the present invention has a constructional feature for provision of the balanced pendulum. It comprises four horizontal shafts, and three links. The first link, which is hung from and has free swings about the first horizontal shaft extending from a lateral inner housing portion of the laser line beam emitting apparatus and passing a portion on the side of its trailing end, has a freely swinging hold on the second link on the side of its leading end through the second horizontal shaft provided in a parallel arrangement with the first horizontal shaft and passing a portion on the side of its leading end. The second link has a swinging hold on the third link on the side of its leading end through the third horizontal shaft which is at right angles to the first and second horizontal shafts on the side of its trailing end and passing a portion on the side of its leading end. The third link has a swinging hold on the pendulum through the fourth horizontal shaft on the side of its leading end. Such the constructive gimbals mechanism contributes to free swings of the pendulum with maintenance of balance. The parallel and perpendicular shafts may be provided in an alternate arrangement.
In the laser line beam emitting apparatus according to the present invention, the stopper has a V-shape sectioned groove into which one side face of the pendulum comes. Accordingly, when the pendulum is held in the groove, it can not swing.
Reception of the pendulum by the V-shape sectioned groove surface of the stopper is performed in accordance with virtual reference surfaces, which may establish a predetermined relative position relationship between the former and latter or suitable position of the received pendulum with maintenance of balance.
When the stopper stops the pendulum from swinging, the laser line beam emitting apparatus having a construction combining the precise formation of the V-shape sectioned groove surface, one side face of the pendulum with an establishment of a precise contact of the outer housing surface thereof with an objective to be examined as well as the precisely formed housing with right-angled emission of the laser beam with respect to a reference surface such as a floor allows the user to know or ascertain a verticality or horizontality of the objective with the emitted laser beam from the laser beam source unit.
The V-shape sectioned groove of the stopper establishes a reference surface on which the lateral surface of the pendulum engages such that the emitted laser beam from the laser beam source unit may provides information of the verticality or horizontarity.